The present invention relates to a vernier calipers whose main beam assembly comprises two legs, specifically to a vernier calipers which can be manufactured easily in that post-assembly work to finish the measuring surfaces for precision is rendered needless.
The main beam of a vernier calipers is usually composed of a single plate. A vernier calipers of such type that the vernier is slidable along two legs has been proposed, in which the main beam is constituted of two round bars extending parallel to each other between the two stoppers at both extremes so that the number of work steps can be reduced and an error due to the thermal strain in working can be prevented.
In this type of vernier calipers whose main beam assembly consists of two legs, however, an assembling error is liable to occur in the main beam assembly itself and the other components; and thereby it becomes necessary after assembling of the instrument to grind and finish the measuring surfaces of the jaws for precision so that these surfaces of the main beam jaw and vernier jaw may make a plane contact with each other within a plane where the two legs intersect with the measuring surfaces at right angles and this work is so difficult as to call for high skill.
It is common practice to integrate the measuring jaws with the main beam assembly and the vernier assembly. Thus in this type of calipers it has been impossible to select the measuring jaws alone, depending on the type of instrument and accordingly to effect standardization of the main beam assembly and the vernier assembly.